Sweetheart Sona feedback
Sweetheart Sona has some very nice visual effects, and hit's a lot of Sona's general visual themes, but just looks wrong in a few areas.
Her pigtails don't look right. From the front it looks like she has 4 of them, and from the top, it looks too busy. I'd suggest removing the top two hair loops, and leaving the bottom two. If you were to bring the points of the bottom hair loops closer together they'd look like a heart from the top as well.
Her top looks strange for Sona as well, and I think it's because the heart pattern is upside down which has her lines going in to out from her collar to her chest (a ^ shape) while her shoulder lines are going out to in from her shoulders to her chest (a V shape). Generally Sona has a V shape with her clothing moving from a wide point at her upper arm tapering in to her chest or waist.
It may look more like a Sona skin if the heart was flipped and the top disconnected from the collar, with the little pink heart currently found on the collar moved to the point at the bottom of the shoulder drape.